380 MEMOIRS OF THE CARNEGIE MUSEUM 



1907, 30 (Para; Guiana). — Eigenmann, Repts. Princeton Univ. Exp. Pata- 

 gonia, III, 1910, 439. 

 Salmo gasteropelecus Pallas, Spic. Zool., VIII, 1769, 80, pi. 3, fig. 4. — Gmelin, 



Syst. Nat., I, iii, 1788, 1384.— Block, Ausl. Fische, III, 1785, 66, pi. 97, fig. 3.— 



Bloch and Schneider, Syst. Ichth., 1801, 418. 



Twelve specimens, 50-64 mm. Mud-flats below Wismar. (I. U. Cat. No. 

 11666.) 



Thirteen specimens, 48-65 mm. Wismar. (C. M. Cat. No. llOla-c; I. U. 

 Cat. No. 11667.) 



Twelve specimens, 42-52 mm. Mora Passage. (C. M. Cat. No. 1099a-c; 

 I. U. Cat. No. 11668.) 



Twelve specimens, 41-51 mm. Trenches of Morawhanna. (C. M. Cat. No. 

 1098rt-c; I. U. Cat. No. 11669.) 



One specimen, Issorora. (C. M. Cat. No. 1100.) 



Fifteen specimens, 48-56 mm. Mud Creek in Aruka River. (C. M. Cat. 

 No. 1097a-c; I. U. Cat. No. 11670.) 



Head 4-4.25; depth 1.75-2; D. 11; A. 31-33; scales 35; nineteen pores in the 

 lateral line; eye 3 in the head, 1.5 in the interorbital. 



Silvery, with a dark line along base of the anal ; a dark band from upper part 



of gill-openings to the caudal ; sometimes narrower lines following the rows of scales 



above this. 



Subfamily Serrasalmin^. 



Serrasalmo Lacepede. 



Serrasalmo Lacepede, Hist. Nat. Poiss., V, 1804, 283. 



Type, Salmo rhombeus Linnseus. 



Belly trenchant, serrate; premaxillary with a single series of teeth; a series of 

 triangular teeth on each side of the palate. 



Key to the Guiana Species of Serrasalmo. 

 a. Caudal margined with white or hyaline; D. 15 or 16; A. 32-37; ventral sense 28-33; head 3 4-; depth 1.6- 

 1.7; cheeks with a naked area (in specimens 120 mm. long) equal to one-half of the second suborbital; 



snout blunt, shorter than the eye. A large diffuse humeral spot g3Tnnogenys. 



aa. Caudal margined with black, the base also black, the hyaline middle area decreasing with age; D. 16 or 17; 

 A. 31-35; serrae 30-36; head 3; depth nearly 2; cheeks entirely covered by the second sub- 

 orbital or a very narrow naked margin; snout acute, especially in the young, at least ecjual to tiie eye 

 in 176-mm. specimens; humeral spot obscure or none rhombeus. 



234. Serrasalmo gymnogenys Giinther. 

 ? Salmo aureus (not of Spix) MtJLLER and Troschel, in Schomburgk, Reisen, III, 

 1848, 637 (Essequibo; Rupununi). 



